Google offers Google Toolbar for Firefox, too.
Long time they didn’t provide any page or product optimised for non-IE users.
This is the first time they create something for users of alternate browsers.
Here is the link: http://toolbar.google.com/firefox/
However, I am already using some Firefox plugins, which show me Google Page Rank – so I won’t install Google Toolbar.
On the other side, there are even more Firefox extensions developed by Google: http://toolbar.google.com/firefox/extensions/